1. Field of the Invention
The present invention relates to a refrigerator, and more particularly, to a mechanism (or an apparatus) for cooling a fresh food compartment of a refrigerator three-dimensionally to homogenize the temperature distribution in the fresh food compartment.
2. Prior Art
A general refrigerator is a household appliance having a fresh food compartment and a freezer compartment for cooling or freezing and/or storing foods in a cold temperature.
FIGS. 1 and 2 are an inner front view and a right side sectional view of a conventional household refrigerator, and FIG. 3 is a schematic horizontal sectional view of a fresh food compartment 4 of the refrigerator shown in FIGS. 1 and 2. As shown in FIGS. 1 and 2, a freezer compartment 6 is air communicated with fresh food compartment 4 through a first and second passageways 11 and 12 in an insulation box 2. A flow of air cooled by an evaporator 15 is directly blown into freezer compartment 6 by a fan 13 and another stream of the cooled air is transferred to fresh food compartment 4 through second passageway 12, and then is supplied into fresh food compartment 4 through a supply port 14. The air having been circulated in fresh food compartment 4 as shown in FIG. 3 (in FIG. 3, the arrow denotes the air flow) is sent back to evaporator 15 through first passageway 11 and the air blown into freezer compartment 6 is also circulated through first passageway 11 back to evaporator 15. However, in the refrigerator having the above described air circulation mechanism, the temperature distribution in fresh food compartment 4 is apt to be not homogeneous and thereby food stored at some section in fresh food compartment 4 may be turned rotten or sour, because fresh food compartment 4 has relatively large bulk compared with that of freezer compartment 6 and the temperature in fresh food compartment 4 is higher, usually above zero degree, than that in freezer compartment 6. Accordingly, that fresh food compartment 4 of a refrigerator should be cooled homogeneously has been strongly required.
U.S. Pat. No. 5,056,332 (issued to Tajima et al.) discloses a refrigerator which is capable of uniformly refrigerating goods in the storage chamber, or the fresh food compartment, by uniformly circulating cold air therein and permits easy access to any goods placed in the refrigerator. The refrigerator has a thermal insulation box which is generally rectangular in horizontal cross section and a storage chamber in the thermal insulating box, and includes rotatable and generally round shelves in the storage chamber and cold air passages formed in a region outside the shelves but within the thermal insulating box and communicating with the storage chamber.
Tajima et al. asserted that such round shelves permit efficient utilization of otherwise non-usable dead corners of the storage chamber, because firstly, the round shelves provide excellent cold air feeding mechanism along the corners of the storage chambers, and they may provide extra space for goods by extending deeply into the rear portion of the refrigerator.
However, in Tajima et al. refrigerator, separate systems for installing and rotating the round shelves are required and thereby manufacturing the refrigerator is relatively difficult and costs much. Further, because the round shelves can exhibit its singular function only when it can rotate, the goods in the storage chamber can be put on an area only in the range of the rotational radius of the shelves, and thereby it can be said that the space-utilizing efficiency of the refrigerator is not so high notwithstanding their assertion, and even low especially when the storage chamber is rectangular. Furthermore, because the temperature distribution in the storage chamber is not homogeneous, separate operations such as rotations of the round shelves are required to cool the goods stored in the storage chamber uniformly.
In the meantime, U.S. Pat. No. 5,074,126 (issued to Mahieu) and U.S. Pat. No. 4,592,209 (issued to Cassanova et al.) disclose a mobile refrigerated chamber for food products and a display counter for food products, refrigerated by forced ventilation. The two Patents disclose systems and methods for circulating air in a display or refrigerated chamber by supplying the air through side wall thereinto. However, a plurality of pipes or pipes having a plurality of pores are utilized in the above methods, and thereby they are not proper to be adopted for a household refrigerator. That is because the space-utilizing efficiency is very important and then unhidden separate members such as pipes take an unnegligible space and thereby deteriorate the space-utilizing efficiency. Further, they cause bed effects on the aesthetics of the chamber.